The invention relates to a carabiner comprising a fixed C-shaped body having a first end shaped as a securing part and a second end for articulation of a gate movable around a pivoting axis between a closed position and an open position, said gate comprising:                a latching part situated opposite the pivoting axis to operate in conjunction with the securing part in the closed position,        a return spring biasing the gate to the closed position,        and a locking ring fitted coaxially around the gate and having a smaller length than that of the gate, said ring being movable between a first locked position enabling the gate to be locked in the closed position and a second unlocked position enabling the gate to be moved to the open position.        